I have used Microsoft's free Synctoy for years. I think it is a brilliant program for Windows to back up a folder/file selection.

There are several benefits (for me) I would mention:

* easy to use and understand.
* you can run a preview without doing anything to check you are getting what you want
* it does a straight copy/ rename/ optional delete depending what actions you pick, without any database
or whatever, so copy is non-proprietary and can be read on anything
* you can save selection, Action, and Options with a name to repeat any time you like.

* To use, make a selection of a source and target folder (a folder pair, called Left and Right)
* you then choose the 'action'
- Syncronise - new and changed files and folders are copied both ways. Renames and deletes on
either side are repeated on the other. Makes Left and Right Identical whatever you have done to
either. To Risky for on the go backup IMO
- Echo - new and changed files and folders on the left are copied to the right, renames and deletes
on the left are repeated on the right. Makes Right match Left.
- Contribute - new and updated files are copied left to right. No deletions. This is my ideal choice for
on-the-go backup to USB. Everything I've added or modified on the laptop is repeated on the backup
but NO deletes.
* there are also several options, one of which is ' check file contents' (verify) but of course that takes
a while


I have all my stuff in a folder called D:\Photos on the laptop hard drive. When I exit Lightroom I backup the catalogue to D:\Photos\LRcatalogue folder.
I then run Synctoy with 'Sync Photos to USB' with a Contribute setting. Result - anything I've done in this session is copied to USB with no mistakes and no deletes on the USB.
I have shortcuts on the desktop so don't even have to look for it so starting it takes seconds.

When I'm on a trip I do this each evening as soon as I have uploaded my SD card/s to the PC, and again if I have fiddled around with lightroom. I Repeat twice to 2 separate USBs so have now have 3 copies. I can happily reformat the SD cards for use again if I choose.


I also have other folder pairs setup to copy to NAS when I get home and to my desktop.

Hi Dave
This is a stack of 20 images, each 3 minutes long. The images (called light frames) were taken with a full frame canon DSLR with the ISO set to 1600 and using 500mm F4.0 canon lens. The lens and camera where piggy backed on a 5 inch Apochromatic refractor that was used for guiding the camera. To guide the setup a Starlight Express lodestar X2 ccd was inserted in the refractor and connected to a laptop computer via USB connection. The computer was also connected to a Losmandy Gemini 2 controller via ethernet. The Gemini 2 controller controlled DC servos on a 25 year old Losmandy G11 mount that I had upgraded with the Gemini 2 controller and DC servos a few of years ago. The computer was running the freeware telescope guiding PHD software that talks to the Gemini 2 controller via the freeware ASCOM platform used for telescope control. With the PHD software you can see star images in real time from the CCD on the computer screen, pick (click on) a reasonable star and PHD software will control the mount to keep the star stationary in field. Note: although the mount will run by itself at sidereal rate, there are always imperfections due to the mechanics and the atmosphere that cause errors without active guiding. I controlled the DLSR via the canon EOS software the comes with the DSLR camera. The camera was also connected to the laptop via a USB connection. Since I'm also a bit of a wuss when it comes to cold weather, once I got the camera in focus I would remote the windows laptop interface and control everything from my windows 10 desktop from inside my office.
For stacking and processing the images I use to use the freeware program deep sky stacker but I splurged and purchased a pixinsight that has a lot more processing control for deep sky images and that is what I reprocessed this image of the Pleaides with. To remove much of the thermal noise from the camera sensor I used ~20 dark frames. Dark frames are images taken with the lens cap on for that same amount of time, with the same ISO setting and ~ the same temperature as the light frames. The dark frames are used by the stacking software to remove thermal noise in the sensor. I also used bias frames to remove any electrical noise from the frames. Bias frames are very short exposure frames are taken with the lens cap on at the same ISO and temperature doesn't matter since these are very short exposures and used by the software to remove any inherent noise added by the read circuit in the camera. The other type of frames used where flat frames which are short exposures taken with the same optical train, ISO and F stop as the light images but with even illumination (typical a white shirt covering the lens and looking at the sky, also a good idea to rotate the shirt between exposures to average out any bias introduced by the shirt. The flat frames are used by the stacking software to remove any vignetting and dust specs that might be in the optical train. (you can look up dark, bias and flat frames on the internet to get details on how to create and use them). If you only do one I find that darks are the most important. If you have any other questions let me know.